1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * DRM driver for Sitronix ST7586 panels 4 * 5 * Copyright 2017 David Lechner <david@lechnology.com> 6 */ 7 8 #include <linux/delay.h> 9 #include <linux/gpio/consumer.h> 10 #include <linux/module.h> 11 #include <linux/property.h> 12 #include <linux/spi/spi.h> 13 #include <video/mipi_display.h> 14 15 #include <drm/drm_atomic_helper.h> 16 #include <drm/drm_damage_helper.h> 17 #include <drm/drm_drv.h> 18 #include <drm/drm_fb_cma_helper.h> 19 #include <drm/drm_fb_helper.h> 20 #include <drm/drm_format_helper.h> 21 #include <drm/drm_framebuffer.h> 22 #include <drm/drm_gem_atomic_helper.h> 23 #include <drm/drm_gem_cma_helper.h> 24 #include <drm/drm_gem_framebuffer_helper.h> 25 #include <drm/drm_managed.h> 26 #include <drm/drm_mipi_dbi.h> 27 #include <drm/drm_rect.h> 28 29 /* controller-specific commands */ 30 #define ST7586_DISP_MODE_GRAY 0x38 31 #define ST7586_DISP_MODE_MONO 0x39 32 #define ST7586_ENABLE_DDRAM 0x3a 33 #define ST7586_SET_DISP_DUTY 0xb0 34 #define ST7586_SET_PART_DISP 0xb4 35 #define ST7586_SET_NLINE_INV 0xb5 36 #define ST7586_SET_VOP 0xc0 37 #define ST7586_SET_BIAS_SYSTEM 0xc3 38 #define ST7586_SET_BOOST_LEVEL 0xc4 39 #define ST7586_SET_VOP_OFFSET 0xc7 40 #define ST7586_ENABLE_ANALOG 0xd0 41 #define ST7586_AUTO_READ_CTRL 0xd7 42 #define ST7586_OTP_RW_CTRL 0xe0 43 #define ST7586_OTP_CTRL_OUT 0xe1 44 #define ST7586_OTP_READ 0xe3 45 46 #define ST7586_DISP_CTRL_MX BIT(6) 47 #define ST7586_DISP_CTRL_MY BIT(7) 48 49 /* 50 * The ST7586 controller has an unusual pixel format where 2bpp grayscale is 51 * packed 3 pixels per byte with the first two pixels using 3 bits and the 3rd 52 * pixel using only 2 bits. 53 * 54 * | D7 | D6 | D5 || | || 2bpp | 55 * | (D4) | (D3) | (D2) || D1 | D0 || GRAY | 56 * +------+------+------++------+------++------+ 57 * | 1 | 1 | 1 || 1 | 1 || 0 0 | black 58 * | 1 | 0 | 0 || 1 | 0 || 0 1 | dark gray 59 * | 0 | 1 | 0 || 0 | 1 || 1 0 | light gray 60 * | 0 | 0 | 0 || 0 | 0 || 1 1 | white 61 */ 62 63 static const u8 st7586_lookup[] = { 0x7, 0x4, 0x2, 0x0 }; 64 65 static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr, 66 struct drm_framebuffer *fb, 67 struct drm_rect *clip) 68 { 69 size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1); 70 unsigned int x, y; 71 u8 *src, *buf, val; 72 73 buf = kmalloc(len, GFP_KERNEL); 74 if (!buf) 75 return; 76 77 drm_fb_xrgb8888_to_gray8(buf, 0, vaddr, fb, clip); 78 src = buf; 79 80 for (y = clip->y1; y < clip->y2; y++) { 81 for (x = clip->x1; x < clip->x2; x += 3) { 82 val = st7586_lookup[*src++ >> 6] << 5; 83 val |= st7586_lookup[*src++ >> 6] << 2; 84 val |= st7586_lookup[*src++ >> 6] >> 1; 85 *dst++ = val; 86 } 87 } 88 89 kfree(buf); 90 } 91 92 static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb, 93 struct drm_rect *clip) 94 { 95 struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0); 96 void *src = cma_obj->vaddr; 97 int ret = 0; 98 99 ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE); 100 if (ret) 101 return ret; 102 103 st7586_xrgb8888_to_gray332(dst, src, fb, clip); 104 105 drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE); 106 107 return 0; 108 } 109 110 static void st7586_fb_dirty(struct drm_framebuffer *fb, struct drm_rect *rect) 111 { 112 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev); 113 struct mipi_dbi *dbi = &dbidev->dbi; 114 int start, end, idx, ret = 0; 115 116 if (!drm_dev_enter(fb->dev, &idx)) 117 return; 118 119 /* 3 pixels per byte, so grow clip to nearest multiple of 3 */ 120 rect->x1 = rounddown(rect->x1, 3); 121 rect->x2 = roundup(rect->x2, 3); 122 123 DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect)); 124 125 ret = st7586_buf_copy(dbidev->tx_buf, fb, rect); 126 if (ret) 127 goto err_msg; 128 129 /* Pixels are packed 3 per byte */ 130 start = rect->x1 / 3; 131 end = rect->x2 / 3; 132 133 mipi_dbi_command(dbi, MIPI_DCS_SET_COLUMN_ADDRESS, 134 (start >> 8) & 0xFF, start & 0xFF, 135 (end >> 8) & 0xFF, (end - 1) & 0xFF); 136 mipi_dbi_command(dbi, MIPI_DCS_SET_PAGE_ADDRESS, 137 (rect->y1 >> 8) & 0xFF, rect->y1 & 0xFF, 138 (rect->y2 >> 8) & 0xFF, (rect->y2 - 1) & 0xFF); 139 140 ret = mipi_dbi_command_buf(dbi, MIPI_DCS_WRITE_MEMORY_START, 141 (u8 *)dbidev->tx_buf, 142 (end - start) * (rect->y2 - rect->y1)); 143 err_msg: 144 if (ret) 145 dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret); 146 147 drm_dev_exit(idx); 148 } 149 150 static void st7586_pipe_update(struct drm_simple_display_pipe *pipe, 151 struct drm_plane_state *old_state) 152 { 153 struct drm_plane_state *state = pipe->plane.state; 154 struct drm_rect rect; 155 156 if (!pipe->crtc.state->active) 157 return; 158 159 if (drm_atomic_helper_damage_merged(old_state, state, &rect)) 160 st7586_fb_dirty(state->fb, &rect); 161 } 162 163 static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe, 164 struct drm_crtc_state *crtc_state, 165 struct drm_plane_state *plane_state) 166 { 167 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 168 struct drm_framebuffer *fb = plane_state->fb; 169 struct mipi_dbi *dbi = &dbidev->dbi; 170 struct drm_rect rect = { 171 .x1 = 0, 172 .x2 = fb->width, 173 .y1 = 0, 174 .y2 = fb->height, 175 }; 176 int idx, ret; 177 u8 addr_mode; 178 179 if (!drm_dev_enter(pipe->crtc.dev, &idx)) 180 return; 181 182 DRM_DEBUG_KMS("\n"); 183 184 ret = mipi_dbi_poweron_reset(dbidev); 185 if (ret) 186 goto out_exit; 187 188 mipi_dbi_command(dbi, ST7586_AUTO_READ_CTRL, 0x9f); 189 mipi_dbi_command(dbi, ST7586_OTP_RW_CTRL, 0x00); 190 191 msleep(10); 192 193 mipi_dbi_command(dbi, ST7586_OTP_READ); 194 195 msleep(20); 196 197 mipi_dbi_command(dbi, ST7586_OTP_CTRL_OUT); 198 mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); 199 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF); 200 201 msleep(50); 202 203 mipi_dbi_command(dbi, ST7586_SET_VOP_OFFSET, 0x00); 204 mipi_dbi_command(dbi, ST7586_SET_VOP, 0xe3, 0x00); 205 mipi_dbi_command(dbi, ST7586_SET_BIAS_SYSTEM, 0x02); 206 mipi_dbi_command(dbi, ST7586_SET_BOOST_LEVEL, 0x04); 207 mipi_dbi_command(dbi, ST7586_ENABLE_ANALOG, 0x1d); 208 mipi_dbi_command(dbi, ST7586_SET_NLINE_INV, 0x00); 209 mipi_dbi_command(dbi, ST7586_DISP_MODE_GRAY); 210 mipi_dbi_command(dbi, ST7586_ENABLE_DDRAM, 0x02); 211 212 switch (dbidev->rotation) { 213 default: 214 addr_mode = 0x00; 215 break; 216 case 90: 217 addr_mode = ST7586_DISP_CTRL_MY; 218 break; 219 case 180: 220 addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY; 221 break; 222 case 270: 223 addr_mode = ST7586_DISP_CTRL_MX; 224 break; 225 } 226 mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); 227 228 mipi_dbi_command(dbi, ST7586_SET_DISP_DUTY, 0x7f); 229 mipi_dbi_command(dbi, ST7586_SET_PART_DISP, 0xa0); 230 mipi_dbi_command(dbi, MIPI_DCS_SET_PARTIAL_ROWS, 0x00, 0x00, 0x00, 0x77); 231 mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); 232 233 msleep(100); 234 235 st7586_fb_dirty(fb, &rect); 236 237 mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); 238 out_exit: 239 drm_dev_exit(idx); 240 } 241 242 static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe) 243 { 244 struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); 245 246 /* 247 * This callback is not protected by drm_dev_enter/exit since we want to 248 * turn off the display on regular driver unload. It's highly unlikely 249 * that the underlying SPI controller is gone should this be called after 250 * unplug. 251 */ 252 253 DRM_DEBUG_KMS("\n"); 254 255 mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF); 256 } 257 258 static const u32 st7586_formats[] = { 259 DRM_FORMAT_XRGB8888, 260 }; 261 262 static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = { 263 .enable = st7586_pipe_enable, 264 .disable = st7586_pipe_disable, 265 .update = st7586_pipe_update, 266 }; 267 268 static const struct drm_display_mode st7586_mode = { 269 DRM_SIMPLE_MODE(178, 128, 37, 27), 270 }; 271 272 DEFINE_DRM_GEM_CMA_FOPS(st7586_fops); 273 274 static const struct drm_driver st7586_driver = { 275 .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, 276 .fops = &st7586_fops, 277 DRM_GEM_CMA_DRIVER_OPS_VMAP, 278 .debugfs_init = mipi_dbi_debugfs_init, 279 .name = "st7586", 280 .desc = "Sitronix ST7586", 281 .date = "20170801", 282 .major = 1, 283 .minor = 0, 284 }; 285 286 static const struct of_device_id st7586_of_match[] = { 287 { .compatible = "lego,ev3-lcd" }, 288 {}, 289 }; 290 MODULE_DEVICE_TABLE(of, st7586_of_match); 291 292 static const struct spi_device_id st7586_id[] = { 293 { "ev3-lcd", 0 }, 294 { }, 295 }; 296 MODULE_DEVICE_TABLE(spi, st7586_id); 297 298 static int st7586_probe(struct spi_device *spi) 299 { 300 struct device *dev = &spi->dev; 301 struct mipi_dbi_dev *dbidev; 302 struct drm_device *drm; 303 struct mipi_dbi *dbi; 304 struct gpio_desc *a0; 305 u32 rotation = 0; 306 size_t bufsize; 307 int ret; 308 309 dbidev = devm_drm_dev_alloc(dev, &st7586_driver, 310 struct mipi_dbi_dev, drm); 311 if (IS_ERR(dbidev)) 312 return PTR_ERR(dbidev); 313 314 dbi = &dbidev->dbi; 315 drm = &dbidev->drm; 316 317 bufsize = (st7586_mode.vdisplay + 2) / 3 * st7586_mode.hdisplay; 318 319 dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); 320 if (IS_ERR(dbi->reset)) 321 return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n"); 322 323 a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW); 324 if (IS_ERR(a0)) 325 return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n"); 326 327 device_property_read_u32(dev, "rotation", &rotation); 328 329 ret = mipi_dbi_spi_init(spi, dbi, a0); 330 if (ret) 331 return ret; 332 333 /* Cannot read from this controller via SPI */ 334 dbi->read_commands = NULL; 335 336 ret = mipi_dbi_dev_init_with_formats(dbidev, &st7586_pipe_funcs, 337 st7586_formats, ARRAY_SIZE(st7586_formats), 338 &st7586_mode, rotation, bufsize); 339 if (ret) 340 return ret; 341 342 /* 343 * we are using 8-bit data, so we are not actually swapping anything, 344 * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the 345 * right thing and not use 16-bit transfers (which results in swapped 346 * bytes on little-endian systems and causes out of order data to be 347 * sent to the display). 348 */ 349 dbi->swap_bytes = true; 350 351 drm_mode_config_reset(drm); 352 353 ret = drm_dev_register(drm, 0); 354 if (ret) 355 return ret; 356 357 spi_set_drvdata(spi, drm); 358 359 drm_fbdev_generic_setup(drm, 0); 360 361 return 0; 362 } 363 364 static void st7586_remove(struct spi_device *spi) 365 { 366 struct drm_device *drm = spi_get_drvdata(spi); 367 368 drm_dev_unplug(drm); 369 drm_atomic_helper_shutdown(drm); 370 } 371 372 static void st7586_shutdown(struct spi_device *spi) 373 { 374 drm_atomic_helper_shutdown(spi_get_drvdata(spi)); 375 } 376 377 static struct spi_driver st7586_spi_driver = { 378 .driver = { 379 .name = "st7586", 380 .owner = THIS_MODULE, 381 .of_match_table = st7586_of_match, 382 }, 383 .id_table = st7586_id, 384 .probe = st7586_probe, 385 .remove = st7586_remove, 386 .shutdown = st7586_shutdown, 387 }; 388 module_spi_driver(st7586_spi_driver); 389 390 MODULE_DESCRIPTION("Sitronix ST7586 DRM driver"); 391 MODULE_AUTHOR("David Lechner <david@lechnology.com>"); 392 MODULE_LICENSE("GPL"); 393